"These are selected because, in my opinion, further delay jeopardizes the recruitment of these eminent researchers and could hinder the medical advances CPRIT believes will result from their work in Texas," wrote Roberts, the agency's interim executive director. "The renowned expertise of these individuals may result in knowledge that leads to conquering the scourge of cancer or, at the very least, make life more tolerable for those with the disease."

Late Monday, Roberts said any further delay places the recruited researchers "at professional risk," because many have already given notice and are in the process of relocating.

A spokeswoman for the governor's office said Monday night that Perry, Dewhurst and Straus were reviewing the letter.

The cancer agency on Dec. 19 froze 160 grants that it awarded in August and early December, following the call by Perry, Dewhurst and Straus for a moratorium on the awarding of taxpayer-funded grants until the agency resolved its problems and restored public confidence.

The problems include improprieties - conflicts of interest, backstage politics and bypassed procedures - in the awarding of three grants totaling more than $60 million. The improprieties led to the resignations of the agency's three top officials, one a Nobel Prize winner, and prompted a number of investigations, one criminal.

In January, state auditors released a withering report listing problems in seven major areas, from how the agency makes grant decisions to how it monitors the spending of public dollars. The audit subsequently received much attention at hearings of the Texas Legislature, which is considering a number of bills on how best to reform the agency.

At a meeting last week, agency governing board members authorized staff to start negotiating contracts on 159 of the grants but not to sign them. Roberts said then that the agency simply wanted to be prepared to move the grants forward without delay whenever the moratorium was lifted.

But on Monday, Roberts told a bolder tack. "This decision is not made without serious and thorough deliberation," he wrote. "I believe CPRIT has sufficiently complied with your December directive to justify moving forward with these extraordinary priorities."